[Fixed] Cerbot call

[Fixed] certbot run call

[Added] Ability to install certbot

[Added] Added webp lib installation

[Improved] Updated nginx app config to only remove trailing slash if …

…it isn't a directory

[Added] Added further useful nginx config items

[Fixed] Fixed sed creating backup file

[Fixed] Fixed markdown typo in readme

[Fixed] Fixed issue with inserting imagick extension for correct php …

…version

[Added] Added gifsicle image optimisation installation